<template>
  <div class="">
    <router-link
      tag="div"
      to="/"
      v-show="showAbs"
      class="header-abs"
    >
      <i class="iconfont header-abs-back">&#xe624;</i>
    </router-link>
    <div
      class="header-fixed"
      v-show="!showAbs"
      :style="opacityStyle"
    >
      <router-link to="/">
        <div class="iconfont header-back">&#xe624;</div>
      </router-link>
      景点详情
    </div>
  </div>

</template>

<script>
export default {
  name: 'DetailHeader',
  data () {
    return {
      showAbs: true,
      opacityStyle: {
        opacity: 0
      }
    }
  },
  methods: {
    handleScroll () {
      const top = document.documentElement.scrollTop
      if (top > 60) {
        let opacity = top / 140
        opacity = opacity > 1 ? 1 : opacity
        this.opacityStyle = {opacity}
        this.showAbs = false
      } else {
        this.showAbs = true
      }
    }
  },
  activated () {
    window.addEventListener('scroll', this.handleScroll)
  },
  deactivated () {
    window.removeEventListener('scroll', this.handleScroll)
  }
}
</script>

<style lang="stylus" scoped>
  @import '~styles/mixins'
  @import '~styles/varibles'
  .header-abs
    position: absolute
    left:.2rem
    top:.2rem
    width: .6rem
    height: .6rem
    border-radius: 50%
    background: rgba(0,0,0,.6)
    text-align:center
    line-height: .6rem
    .header-abs-back
      color:#fff
      font-size: .3rem
  .header-fixed
    z-index: 2
    height: $headerHeight
    line-height: $headerHeight
    text-align:center
    color:#fff
    background:$bgColor
    font-size:.32rem
    position:fixed
    top: 0
    right: 0
    left: 0
    .header-back
      position:absolute;
      width: .64rem
      text-align:center
      font-size: .3rem
      top:0
      left:0
      color:#fff
</style>
